1. Field of the Invention
The present invention generally relates to a wireless communication device, and more particularly, to a device and method for receiving and processing a Hybrid Automatic Repeat reQuest (HARQ) signal in a wireless communication device.
2. Description of the Related Art
HARQ is a transmission method that improves a delay problem in an upper layer by adding channel coding, for utilizing an error packet, to existing Automatic Repeat reQuest (ARQ). HARQ is used in mobile communication standards such as High Speed Packet Access (HSPA) and Long Term Evolution (LTE). In a HARQ scheme, an error packet received in a previous process is stored in a form of a log likelihood ratio (LLR) signal. With the increase of transmission speed in mobile communication, the size of HARQ memory has increased.
A mobile communication terminal usually includes a HARQ signal processor to process HARQ burst data. The HARQ signal processor requires HARQ memory to store data for the processing of the HARQ burst data.
Generally, an internal memory within a modem of a terminal or an external memory outside the modem is used as HARQ memory. A technique of using both the internal memory and the external memory as a buffer of a HARQ data processor is disclosed in Korean Patent Publication No. 2010-0009185.
When the internal memory is used as the buffer, read and write operations can be performed quickly and power consumption is low. However, since the size of HARQ information is fairly large, when the internal memory is used as the buffer, a chip size increases, causing the price of the chip to increase. In addition, when the size of the HARQ buffer needs to be expanded, expansion cannot be supported, decreasing expandability.
When the external memory is used as the buffer, an existing memory module is used together with a modem chip of the terminal, and therefore, the buffer can be easily implemented with almost no additional cost, and a HARQ memory size can easily be expanded. However, when the external memory is used as the buffer, power consumption is greater than when the internal memory is used.